智能变电站过程层网络关键对象建模与仿真

为满足智能变电站过程层网络及自动化应用系统的性能分析需求,提出了基于OPNET（optimized network engineering tools）的变电站过程层网络建模与仿真方法。基于变电站自动化系统应用需求,分析了实体设备、IEC 61850标准、调度策略和组网结构的建模要求,研究了变电站过程层网络关键对象的建模方法。结合220 kV典型变电站,构建了完整的变电站过程层网络性能分析模型,分析了正常运行和故障运行状态下的网络性能,为开展智能变电站过程层网络及其自动化系统的性能分析提供了研究工具。     

Linear networks depending polynomially on parameters: dynamic behaviour for large values subject to tolerance errors

This paper is concerned with linear networks depending polynomially on parameters, when considering large values of the parameters, and their corresponding ideal networks—i.e. the networks in which all parameters are set equal to infinity. It has been taken into account that only the specification of nominal values and tolerances—and not of actual values—is physically meaningful. The stability of the ideal networks and the least hypotheses that allow us to use a previous algorithm to find monomial functions—in a single suitable variable—that describe arbitrarily large nominal values which ensure stability within a suitable constant tolerance are assumed. An integer h such that while these nominal values go to infinity then for any smooth causal excitations bounded together with their first h derivatives—in particular, for any smooth eventually periodic causal excitations—the zero‐state response of the actual networks converges uniformly on the whole time axis to that of the ideal networks is proved to exist. The proof may be used as an algorithm. An example which proves that the found class of excitations may be not the widest is given. The application of the results to the evaluation of the synchronization error due to high but finite values of the parameters in an ideally synchronizing linear network is shown. Copyright © 1999 John Wiley & Sons, Ltd.     

动态神经网络对功率放大器的建模方法及要点

为了使基于神经网络的功率放大器的行为级建模变得更加灵活且易于实现,主要介绍了动态神经网络应用于功率放大器的建模方法及要点。首先简单介绍了动态神经网络的模型和理论,然后说明了对功率放大器进行建模时所采用的方法。重点讲述了动态神经网络对功率放大器建模过程中的几个要点,包括:如何选择动态神经网络隐层神经元数目和导数阶数、如何确立功率放大器输出电压表达式、长期记忆效应的建模、动态神经网络在仿真软件中收敛性等问题。注意这些要点之后,神经网络模型仿真结果会具有良好的收敛性和准确性,这样就能快速地完成功率放大器的建模以应用到实际系统的设计和优化之中。     

计及恶劣天气时空相关性的弹性配电网储能电站多层规划方法

针对恶劣天气下配电网应对极端事故的系统弹性提升问题,提出了计及复合自然灾害时空相关性的配电网储能电站多层规划方法。首先建立了恶劣天气下考虑暴雨强度与风速相关性的联合灾害强度概率分布模型,通过对复合灾害强度分布特征与配电网元件运行风险之间的多维时空相关性分析,构建了计及复合自然灾害时空相关性的配电网故障风险模型。其次提出了复合灾害天气下提升配电网运行弹性的储能电站多层规划策略,构建了考虑灾害时空分布特征的储能配置-风险建模-配网调度的储能电站规划模型架构,并基于Benders分解将其转化为三层混合整数非线性规划问题进行高效求解。通过典型配电网的仿真测试和对比分析可知,所提方法能够有效提升恶劣天气下配电网应对故障风险的运行弹性和恢复能力,保障灾害事件下配网重要负荷的可靠供电。     

Kruskal's Maximal Spanning Tree Algorithm for Optimizing Distribution Network Topology to Improve Voltage Stability

Abstract—Alteration of power network topology is often required to meet important objectives, such as restoring connectivity, minimizing power losses, maintaining stability, maximizing power transfer capability etc., and is achieved by switching of circuit breakers and other switching devices in the power network. Primary power distribution networks are often interconnected and meshed but should be transformed to radial topology to achieve various operational advantages. Distribution networks also need to be reconfigured after faults to restore power at all the load points. Reconfiguring a power network, however, is a complicated multi-constrained optimization problem, as there may exist many feasible switching combinations in a large power network. This article proposes a novel application of graph theory, supported by Kruskal's maximal spanning tree algorithm, to search for the optimal network topology and to optimally convert an interconnected meshed network into a radial system to achieve best operational characteristics, cost, and control. The proposed technique has been demonstrated on a 30-node primary distribution network originally having a mesh topology, and the results indicate significant performance improvement after transformation into optimal radial topology.     

基于多端网络等效变换的大型网络分析

本文提出了利用多端网络等效变换来简化电路的大型网络分析方法。     

Volt-VAR control for distribution networks with high penetration of DGs: An overview

Continuously improving the ability to accept distributed renewable energies is the trend of future grid development, and a large number of papers have been published in recent years to study the problem of Volt-VAR control (VVC) for distribution networks with high penetration of distributed generations. This paper summarizes the relevant modeling and solution methods for VVC problems, mainly including VVC based on multiple time scales, hierarchical partitioning, multi-stage and network reconstruction, in conjunction with the operational characteristics of distribution networks containing distributed renewable energies; meanwhile, it analyzes the advantages and disadvantages of traditional optimization methods, heuristic intelligent algorithms and random variable processing methods used to solve VVC problems, and then introduces the application of model-free deep reinforcement learning as a latest decision method in VVC of distribution networks. Most of the models and methods compiled in this article are from the research results of the last three years and have some reference value.     

中压配电网电力线载波通信信道建模

电力线载波通信是智能配电网通信技术的重要选择之一。而中压配电网结构复杂,分支众多,存在电缆-架空线混合型线路,使得载波信号在其上的传输特性难以预估。结合中压配电网结构特点,提出一种载波信号在混合型配电网络中的信道建模方法。首先,在中压配电网的实际拓扑结构及线路类型基础上,定义了载波信号的传输线管道。然后,结合多导体传输线理论和行波理论,推导各传输线管道的传播矩阵及各节点的散射矩阵,并根据网络拓扑关系列写整个网络的电压方程。最后,由电压方程可求得在信源节点激励下全网任意节点的电压响应。该建模方法不受网络拓扑结构及线路类型限制,具有很强的适应性及可移植性。计算及电路仿真结果表明了方法的正确性及有效性。     

一种配电网络拓扑快速增量建模方法

将配电网中的开关和T接点看作节点、将馈线段当作边,采用邻接表描述节点和边的连接关系,用从属关系反映配电变压器与边的连接关系。提出一个14列的拓扑编辑表记录编辑操作,每行反映一次编辑操作。详细描述了节点添加、节点删除、节点类型变更、边的添加和删除等基本编辑操作的处理方法,论述了拓扑变更后边与配电变压器从属关系调整方法,论述了根据拓扑编辑表进行配电网络拓扑的快速增量建模的方法,结合实例对提出的方法进行了分析和说明,结果表明提出的方法是可行的。     

Artificial neural network and non-linear models for prediction of transformer oil residual operating time

This paper presents two modeling techniques for the prediction and monitoring of the characteristics of transformer oil. The first employs artificial neural network (ANN) and the second employs non-linear modeling (nlm). The proposed techniques are implemented for predicting the transformer oil residual operating time (t_rot) which is defined as the service period after which the breakdown voltage (BDV) violates the limits given in the standard specifications.The selection of the most influential characteristics on residual operating time (t_rot) in the proposed techniques is obtained by statistical analysis. The non-linear model depends on linear combination of non-linear functions for each characteristic. The ANN technique for modeling these characteristics preserves the non-linear relationship between these characteristics and (t_rot). The results are compared with previously published modeling techniques namely multiple linear regression and polynomial regression models. Different evaluation indices have been used to justify the superiority of the proposed modeling techniques for predicting (t_rot).     

国电北京宽带数据城域网建设

介绍了国电北京宽带数据城域网的建设概况以及其中使用到的IP环网技术、MPLS VPN技术，并详细介绍了该数据网的主要技术特点，包括骨干网建设、接入层建设等。     

分布式光伏与风电机组LVRT及电流限幅环节的等值建模

随着分布式新能源机组的持续并网,电力负荷的动态特性已发生显著变化,需要研究主动配电网等值建模新方法。主动配电网中分布式新能源机组类型呈现多样化,控制器存在切换以及限幅等非线性环节。对此,针对双馈风电机组、直驱永磁风电机组和光伏电源模型结构的共性,构建了可描述多类型分布式新能源机组动态特性的通用模型。在此基础上提出了多激励影响下分布式新能源机组低电压有功管理、低电压无功管理以及电流限幅等非线性环节的非机理等值建模新方法,并基于简单算例进行了验证。对某实际主动配电网进行建模仿真,结果表明：将所提等值模型与传统负荷模型并联,可较为准确地描述计及分布式新能源机组低电压穿越(LVRT)和电流限幅环节的主动配电网的动态特性。     

新能源接入背景下的谐波源建模方法综述

大量接入可再生能源和逐步采用交直流混合网络已经成为现代电力系统的两大特征,随之而来的电网谐波问题日益突出。在此背景下,谐波源建模方法、谐波溯源方法以及谐波治理方法这三个难点问题越来越受到学术界和工业界的高度关注。综述了目前常见的谐波源建模方法,为电网谐波领域的理论研究和实践提供参考。从谐波源的机理性建模和数据驱动建模两个角度,对目前常见的谐波源时域建模方法和频域建模方法进行了梳理、分析和比较,归纳了各种建模方法的优势和不足,论述了各类谐波源建模方法的适用场景。其中,重点阐述了机理性建模方法和数据驱动建模方法存在的问题,并针对每个问题提出了对应的解决思路。最后,对常见谐波源建模方法的特点进行了归纳总结,对新能源接入背景下谐波源建模技术的发展方向进行了展望。     

不确定因素耦合下输电网风险规划研究综述

传统的确定性风险分析方法由于存在多种弊端,难以适应新形势下的输电网规划和方案评估,为了更加合理地管控输电网风险水平,基于概率性分析方法对输电网风险规划和评估等研究成果进行了综述。介绍了输电网中的安全、设备、结构、管理和市场等一系列风险因素及相应建模方法;从场景规划、随机规划、模糊规划和区间规划等方面,评述了考虑多种不确定因素的输电网风险规划方法;基于评估指标和方法,综述了近年来国内外考虑多种不确定因素的系统风险评估体系研究成果。在此基础上,结合高比例可再生能源、交直流混联、网源协调、需求响应和建模优化等研究热点,展望了未来考虑多种不确定因素的输电网风险规划领域中需要关注的问题。     

多能源网络的广义电路分析理论——（二）网络模型

以电力、热力、燃气网络为代表的多能源网络是世界上最为复杂的物理网络之一,是连接能源生产和消费的重要传输环节,也是多能源系统耦合的重要途径。文中借鉴电力系统分析中"矩阵化"与"外端口等值"的思想,基于多能源网络支路层的广义电路模型,提出了网络层的广义电路分析理论。首先,针对多能源网络高维动态特性难以描述的问题,以支路广义电路模型为基础提出了拉普拉斯域通用多能源网络建模方法,并建立了矩阵化的紧凑模型。其次,提出了多能源网络的外端口等值方法,等效地将复杂的内部信息转换为等值的边界条件,既能解决多能源网络的联合分析难题,同时又很好地保护各能源系统数据信息隐私。最后,分别结合热力网络与燃气网络的实际特点,提出了热力网络与燃气网络的全网络广义电路模型与边界等值方法。     

dynoNet: A neural network architecture for learning dynamical systems

This article introduces a network architecture, called dynoNet, utilizing linear dynamical operators as elementary building blocks. Owing to the dynamical nature of these blocks, dynoNet networks are tailored for sequence modeling and system identification purposes. The back-propagation behavior of the linear dynamical operator with respect to both its parameters and its input sequence is defined. This enables end-to-end training of structured networks containing linear dynamical operators and other differentiable units, exploiting existing deep learning software. Examples show the effectiveness of the proposed approach on well-known system identification benchmarks.     

华中电网分布式网络建模与实时信息共享方案

分析了当前调度控制中心网络建模的现状和存在的问题,根据华中电网的运行特点和实际情况,设计了一套分布式网络建模与实时信息共享方案.该方案提出按调度范围实现分布式建模与数据采集的原则,在进行设备命名规范化的基础上,进行网调与省(直辖市)调模型的拼接,形成全网模型.该方案还对模型拼接流程、公共信息模型(CIM)优化方法、实时信息共享等进行了详细说明.     

基于预处理BP神经网络的开关磁阻电机建模

针对开关磁阻电机(SRM)强耦合、强非线性、难以精确解析建模的问题,提出一种基于数据预处理的反向传播(BP)神经网络建模方法。首先通过传统直流脉冲法测量一个电周期内SRM静态电磁特性,获取建模样本数据;其次充分利用电机先验知识,通过可以初步反映SRM非线性特性的磁链和转矩解析表达式对实测样本数据进行预处理并作为BP神经网络新的输入,降低神经网络拟合误差。与传统BP神经网络建模的对比结果显示,引入预处理方法可以有效减少BP神经网络节点数量,增强神经网络泛化能力,提高神经网络建模精度。     

ART-2与CMAC网络的性能对比研究

在分别介绍ART-2及CMAC的网络结构和算法的基础上，分析了两种网络在结构以及性能上的相同点和不同点。并采用各自网络进行了建模的应用，其中根据ART-2的特点在其顶部增加了一层额外的输出层。最后根据各自网络对同一非线性电机速度控制系统的建模结果，对ART-2及CMAC网络的特性及适用范围进行了较深入的讨论。